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#include <bits/stdc++.h>


using namespace std;


struct edge {
    int u, v, w;
};

struct segment {
    int l, r, prod;

    bool operator!=(const segment &other) const {
        return l != other.l || r != other.r || prod != other.prod;
    }
};

void extendSegs(vector <segment> &segs, const segment &s) {
    if (segs.empty() || segs.back().prod != s.prod) {
        segs.push_back(s);
    } else {
        segs.back().r = s.r;
    }
}

int solve(int n, vector <int> &p, vector <edge> &edges) {
    sort(edges.begin(), edges.end(), [&](const edge &a, const edge &b) {
        return make_tuple(a.w, a.u, a.v) < make_tuple(b.w, b.u, b.v);
    });

    vector <vector<edge>> g(n);

    edge eLast = {-1, -1, -1};
    for (auto &e : edges) {
        if (e.u == eLast.u && e.v == eLast.v && e.w == eLast.w) {
            continue;
        }

        g[e.v].push_back(e);
        eLast = e;
    }

    vector <vector<segment>> segs(n);
    segs[n - 1] = {{1, p[n - 1], 1}};

    vector <bool> changed(n, false);
    changed[n - 1] = true;

    vector <segment> segsPrev, segsJoint;
    while (*max_element(changed.begin(), changed.end())) {
        vector <bool> changedNew(n, false);

        for (int v = 0; v < n; v++) if (changed[v]) {
            int wLast = -1;
            for (auto &[u, _, w] : g[v]) {
                if (w != wLast) {
                    segsPrev.clear();

                    for (auto [l, r, prod] : segs[v]) {
                        l = max(1, (l + w - 1) / w);
                        r /= w;

                        if (l <= r) {
                            extendSegs(segsPrev, {l, r, prod * w});
                        }
                    }
                }

                wLast = w;
                segsJoint.clear();

                int lCurr = 1, segsIdx = 0, segsPrevIdx = 0;
                while (true) {
                    bool segsFinished = segsIdx == (int) segs[u].size();
                    bool segsPrevFinished = segsPrevIdx == (int) segsPrev.size() || segsPrev[segsPrevIdx].l > p[u];

                    if (segsFinished) {
                        if (segsPrevFinished) {
                            break;
                        }

                        extendSegs(segsJoint, {lCurr, min(segsPrev[segsPrevIdx].r, p[u]), segsPrev[segsPrevIdx].prod});
                        segsPrevIdx++;
                    } else if (segsPrevFinished) {
                        extendSegs(segsJoint, {lCurr, segs[u][segsIdx].r, segs[u][segsIdx].prod});
                        segsIdx++;
                    } else {
                        extendSegs(segsJoint,
                            {
                                lCurr,
                                min(segs[u][segsIdx].r, segsPrev[segsPrevIdx].r),
                                max(segs[u][segsIdx].prod, segsPrev[segsPrevIdx].prod)
                            }
                        );

                        if (segs[u][segsIdx].r <= segsJoint.back().r) segsIdx++;
                        if (segsPrev[segsPrevIdx].r <= segsJoint.back().r) segsPrevIdx++;
                    }

                    lCurr = segsJoint.back().r + 1;
                }

                bool same = true;
                if (segs[u].size() != segsJoint.size()) {
                    same = false;
                } else {
                    for (int i = 0; i < (int) segs[u].size(); i++) if (segs[u][i] != segsJoint[i]) {
                        same = false;
                        break;
                    }
                }

                if (!same) {
                    changedNew[u] = true;
                    segs[u] = segsJoint;
                }
            }
        }

        changed = changedNew;
    }

    if (segs[0].empty()) {
        return -1;
    } else {
        return segs[0][0].prod;
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int t;
    cin >> t;

    while (t--) {
        int n, m;
        cin >> n >> m;

        vector <int> p(n);
        for (int &pi : p) {
            cin >> pi;
        }

        vector <edge> edges(m);
        for (auto &[u, v, w] : edges) {
            cin >> u >> v >> w; u--; v--;
        }

        cout << solve(n, p, edges) << '\n';
    }

    return 0;
}